Treatment of wool fibers



temperatures enabl ngthis; ai

Patented Aug. 27, 1946 TREATMENT OF wool. FIBERS John Bamber Speakman and Thomas Barr, Leeds,

England, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing. Application July 15, 1943, Serial No.

494,848. In Great Britain August 21, 1942 .The present invention relates to a treatment of loose fiber or yarn or woven or knitted fabric consisting of or containing wool fibers, whereby novel effects are produced. These effects include an increased stiffness,'a reduced affinity for water vapour and a diminished tendency to felt o for woven or knitted fabrics, to.shrink.

" 6 Claims. (Cl. 117-141) According to the invention, material of the kind described is exposed at elevated temperature, but below 100 0., to the combined action of water vapour and the vapour of a volatile monomeric monovinylidene compound containing a CH2=C= group, for instance, an ester of acrylic or methacrylic acid, styrene or a vinyl ester.

If the material is wetted out with water before exposure to the action of the mixed vapours. more even effects are obtained. The wetting out may be effected by exposing the material to water vapour alone, before exposing to the action of the mixed vapours. Alternatively, when it is required to use a polymerisation catalyst to promote polymerisation of the mono-vinylidene compound on and within the fibers, the material may be impregnated with an aqueous solution containing the catalyst, for example ammonium persulphate. Or the material may be immersed in water or in water containing a wetting agent.

'One of the aims ofthe invention isto effect polymerisation of.-monomericvinylidene compounds preferentially withinthe3;,.1ibers; .It is believed that the application oflthese compounds-j to fibers swq il ri {with .water apour; at elevated be, realised.

T e" time armament of :with the cited; dGSiIBdJ ILi-IQ example; anun- I shrinkable finish on allx-wooljfabrics is required, I

.using methylmethacrylate,-treatment is carried 4 out until the fabrics show anfiricrease in weight of 40% or more." Using'styrene, a considerable:

reduction in shrinking powerfis also given by continuing the treatment. until the fabrics show andncreasein-weight of about 13%; For increased stifiness, the amount of polymer to be- I deposited must, of course, increase with the degree of stiffness desired. It is, however, p'ossiblcto continue the'treatinent of the materials accord ing to the invention until the increase in weight is as much as 200%..

When polymers are formed alsofills the space normally available for accommodating water, with the result that materials" e material varies within wool fibers; the groups normally conferringafflnity for water are occupied or maskedby the polymer, which treated according to .the invention possess a reduced aflinity for water vapour. In addition, polymer deposition within the fibers modifies their elastic properties by offering hindrance to relative movement of the protein molecules. Both the reduced aifinity for water vapour and the mechanical hindrance come into play in increasing the stiffness of the fibers and in preventing that type of. fiber movement which is necessary with loose fiber, as well as'with woven and knitted fabrics containing wool, if there is to be felting.

' As felting is normally accompanied by shrinkage in the case of knitted or woven fabrics containing wool fibers, treatment according to the invention prevents or reduces that type of shrinkage known as milling shrinkage- Further, when polymer is deposited on the surface of, as well as within, wool fibers, the surface scale structure is masked and a supplementary eifect in minimising milling shrinkage is thu obtained.

The invention is illustrated but not limited by the following examples, in which the parts are expressed by weight: v

Exampleif Wool fabric (1 part air-dry weightlisiwetted 4 out in watery-wrung until about; Ipart. of'water i 5 with a; refluxcondenseifabric in that it possessesia fuller handle and shows reduced.shrinkagelin soap mi 1l ing.- {For d m e," he m t rnsio t hea ed a dtreated fabricate milled ogetherinjfiyalaqueous e h ink seem' percent Untreated.-. 1645.

Treated remains, and wound at open-- width xinto ailoose roll, which is suspended above a mixturpf methyl methacrylate -(2 parts) andwater part). contained ima; water iaclketed; vessel which is'ifit'tedf the =fabric i not .contajminate on nsate.

the "fabric, is removedmfro e el an increase 'inweightoi-about 49.7 (in tit-d pos I tion. of. methyl methacrylat fwithin-theiibers. e 'smtreatfldfabfie di ters 1mm, the enamel a i soap solution, the fbllowin .obtainedr] d'sitiodithat --i i.- shrinkage,

' 3 Example 2 W001 fabric (1 part air-dry weight) is impregnated with a 02% aqueous solution of ammonium persulphate and expressed until 1-1.5 parts of solution remain. The fabric is then suspended at 90-95 C. in the vapour from a mixture of methyl methacrylate (2 parts) and water (1 part) as described in Example 1.. In this case,'the methyl methacrylate contain 0.5% --copper rosinate as a non-volatile polymerisation inhibitor. Polymerisation occurs on the fabric,"

which shows after 30 minutes anincrease in weight of about 80%, and after 1 hour an increase in weightof about 1 50%.v A q When patterns of the treated and untreated fabrics are milled together in- 5% aqueous soap solution, the following area shrinkages are -ob- I Example 3 I wool fabric 2 parts air-dry weight)" is wetted out in water and expressed ,until about 2 partsof water remain. The fabric is then treated at 90"-95 .0. in the vapour from a mixture of styrene (2 parts) and water (1 part) as described in Example 1. After six hoursthe fabric is conditioned in air, and it shows an increase in weight of about 13%.

When patterns of the treated and untreated fabrics are milled together in 5% aqueous soap solution, the following" area shrinkages are obtained: 1

. Area Fabric shrin z i per cent Untreated 38. 0 Treated 16.4

We claim:-

'1. Process for the production of novel effects on wool-fiber-containing textile material which comprises exposing such material at anelevated temperature of the order of 90 -95.C. to the com bined action of water vapor and the vapor of a volatile monomeric polymerizable compound containing, a CHz=C= group and selected from the class consisting of esters of acrylic acid, esters of methacrylic acid, styrene and vinyl esters until polymer is formed within the fibers.

2. Process of claim lj wherein the material is wetted out with water before exposure-to'the action of the mixed vapors.

v3. Process of claim 1 wherein the textile material is impregnated with a polymerizationgcatalyst before exposureto the action of the mixed vapors.

4. Processof claim 1 wherein the polyme izable monomer is methyl methacrylate.

5. Process of claim 1 wherein, the polymerizable monomer is methyl methacrylate and'the textile material is, impregnated with a 0.2% aqueous solution of ammonium persulfate before exposureto the action of the mixed vapors.

6. Process of claim 1 wherein the polymerizable monomer is styrene.

JOHN BAMBER. SPEAKMAN.. THOMAS BARR. 4 

